This application claims the priorities of Japanese Patent Application Nos. 10-32214, 10-32215, and 10-32216, each filed on Jan. 29, 1998, and Japanese Patent Application No. 10-98376 filed on Mar. 26, 1998 which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a three-dimensional image scanner for capturing three-dimensional form information and pattern information of an object to be measured and generating a three-dimensional image of the object; and, in an optical apparatus in which a light source and a heat-sensitive section are accommodated in a common housing, to a heat-insulating device provided with a heat-insulating partition for inhibiting the heat generated by the light source from being transmitted to the heat-sensitive section.
2. Description of the Prior Art
In the fields of computer graphics, plastic surgery, and the like, a three-dimensional image scanner is employed as an input device for three-dimensional images. In general, the three-dimensional image scanner is configured such as to capture three-dimensional form information and pattern information of an object to be measured and generate a three-dimensional image of the object according to thus captured three-dimensional form information and pattern information.
Though a three-dimensional measuring device using a probe, an optical cutting device using an optical sensor, or the like can be chosen as a device for capturing the three-dimensional form information of the object to be measured, the three-dimensional form information can easily be captured in a short time if a moire device is employed.
When a grating shadow type moire device, which is a typical example of moire device, is used, then the following problems may occur.
Namely, as shown in FIG. 5, a grating shadow type moire device is configured such that light from a point light source P1 irradiates an object to be measured 2 by way of a reference grating 102, and a deformed grating image formed on the object 2 is observed through the reference grating 102 at an observing point P2, so as to yield an image formed with moire fringes. In this grating irradiation type moire device, however, the size of the measurable object 2 is restricted by the size of the reference grating 102, and the object 2 is needed to be placed in front of the reference grating 102, whereby there may occur a problem that the degree of freedom in measurement decreases.
In view of such circumstances, it is a first object of the present invention to provide a three-dimensional image scanner which can capture three-dimensional form information of an object to be measured easily in a short time with a high degree of freedom in measurement.
Further, since the reference grating 102 exists, the above-mentioned grating irradiation type moire device cannot be used, as it is, for capturing the pattern information of the object 2. For capturing this information, it is necessary to take a two-dimensional image of the object 2 with the reference grating 102 being removed so that no moire fringes are formed. Since the reference grating 102 is considerably large, it cannot easily be removed.
In view of such circumstances, it is a second object of the present invention to provide a three-dimensional image scanner which can easily capture pattern information of an object to be measured, while being able to capture three-dimensional form information of the object easily in a short time with a high degree of freedom in measurement.
In an optical apparatus provided with a light source such as lamp, like the moire device mentioned above, the light source acts as a heat source so as to thermally influence its surroundings. In the case where a heat-sensitive section such as a light-receiving element or control circuit which is likely to be influenced by temperature is accommodated in the same housing with the light source, it is necessary to provide a heat-insulating structure for inhibiting the heat generated by the light source to be transmitted to the heat-sensitive section.
Therefore, an exhaust fan has conventionally been disposed at an outer wall portion of the housing, so as to discharge the air heated by the light source to the outside.
Simply providing an exhaust fan, as in the conventional cases, may not yield sufficient heat-insulating effects, however.
For example, in the case where a grating projection type moire device which is configured such as to capture not only the three-dimensional form information but also pattern information of an object to be measured employs a structure for illuminating the object with an illumination lamp, the illumination lamp often has to be disposed relatively close to the imaging section of a CCD camera or the like. In such a case, it is difficult to sufficiently inhibit the heat generated by the illumination lamp from being transmitted to the imaging section by simply providing an exhaust fan. Such a problem can similarly occur in other optical apparatus as well.
In the case employing a configuration in which a first partition for separating the light source and the heat-sensitive section from each other and a second partition disposed on the light source side of the first partition are disposed such as to form a cooling passage for guiding the heat generated by the light source to the exhaust fan, the ventilation efficiency in the cell defined by the first partition can be enhanced. This can suppress the temperature rise in the first partition, thereby inhibiting the heat from being transmitted to the heat-sensitive section through the partition to some extent.
In the case where the heat-sensitive section is extremely sensitive to heat, as in the case of CCD camera or the like, there is a demand for further effectively inhibiting the heat from being transmitted to the heat-sensitive section.
In view of such circumstances, it is a third object of the present invention to provide, in an optical apparatus in which a light source and a heat-sensitive section are accommodated in a common housing, a heat-insulating device which can effectively inhibit the heat generated by the light source from being transmitted to the heat-sensitive section.
The three-dimensional image scanner in accordance with a first aspect of the invention achieves the first object of the present invention by capturing three-dimensional form information by using a grating projection type moire device.
Namely, the three-dimensional image scanner in accordance with the first aspect of the present invention is a three-dimensional image scanner for capturing three-dimensional form information and pattern information of an object to be measured and generating a three-dimensional image of the object according to thus captured three-dimensional form information and pattern information,
wherein the three-dimensional form information is captured by a grating projection type moire device.
Preferably, the grating projection type moire device comprises grating moving means for moving at least one of a projection grating provided in a projection optical system of the grating projection type moire device and an observation reference grating provided in an observation optical system of the grating projection type moire device in a direction orthogonal to grating lines of both of the gratings within a plane orthogonal to optical axes of both of the optical systems.
Preferably, the grating projection type moire device further comprises fringe scanning means for determining, according to a plurality of sets of three-dimensional form information captured at individual moving positions of at least one of the projection grating and observation reference grating moved by the grating moving means, an irregular form of each part of the tree-dimensional form information.
Here, xe2x80x9cgrating projection type moire devicexe2x80x9d refers to a moire device comprising a projection optical system and an observation optical system, whose optical axes are in parallel to each other, in which an image of a projection grating is projected by the projection optical system onto the object to be measured, and the deformed grating image formed on the object is focused on the observation reference grating by the observation optical system, such that the resulting moire fringes are observed.
The three-dimensional image scanner in accordance with a second aspect of the present invention captures the three-dimensional form information by using a grating projection type moire device, and the pattern information by using an observation optical system of the grating projection type moire device, thereby achieving the second object.
Namely, the three-dimensional image scanner in accordance with the second aspect of the present invention is a three-dimensional image scanner for capturing three-dimensional form information and pattern information of an object to be measured and generating a three-dimensional image of the object according to thus captured three-dimensional form information and pattern information,
wherein the three-dimensional form information is captured by a grating projection type moire device, and the pattern information is captured by an observation optical system of the grating projection type moire device.
Preferably, the grating projection type moire device further comprises grating retracting means for retracting at least one of a projection grating provided in a projection optical system of the grating projection type moire device and an observation reference grating provided in the observation optical system to a position deviated from an optical path of the optical system corresponding thereto when capturing the pattern information.
The three-dimensional image scanner in accordance with the third aspect of the present invention captures the three-dimensional form information by using a grating projection type moire device, and the pattern information by using an observation optical system of the grating projection type moire device, and an illumination lamp exclusively used for irradiating the object to be measured is turned on when capturing the pattern information, thereby achieving the second object.
Namely, the three-dimensional image scanner in accordance with the third aspect of the present invention is a three-dimensional image scanner for capturing three-dimensional form information and pattern information of an object to be measured and generating a three-dimensional image of the object according to thus captured three-dimensional form information and pattern information,
wherein the three-dimensional form information is captured by a grating projection type moire device, and the pattern information is captured by an observation optical system of the grating projection type moire device; and
wherein, when capturing the pattern information, an illumination lamp different from a projection lamp provided in a projection optical system of the projection type moire device is turned on such as to irradiate the object.
Preferably, the projection lamp is turned off when the illumination lamp is turned on.
Preferably, when capturing the pattern information, an observation reference grating provided in the observation optical system is retracted to a position deviated from an optical path of the observation optical system.
The heat-insulating device in accordance with a fourth aspect of the present invention is a heat-insulating device in an optical apparatus in which a light source and a heat-sensitive section are accommodated in a common housing while being separated from each other by a heat-insulating partition such as to inhibit the heat generated by the light source from being transmitted to the heat-sensitive section,
wherein the heat-insulating partition comprises at least two partition walls forming a cooling/heat-insulating path.
Here, the xe2x80x9clight sourcexe2x80x9d is not restricted to any particular kind of light sources as long as it is a heat radiation type light source which may adversely affect the heat-sensitive section.
The xe2x80x9cheat-sensitive sectionxe2x80x9d is not restricted to any particular element as long as it may adversely be affected by the heat generated by the light source, and examples thereof include light-receiving elements, electric circuits, control circuits, precision instruments, and the like.
Preferably, the cooling/heat-insulating path is provided with an intake port for forcibly causing air from outside to flow through the cooling/heat-insulating path, and an exhaust unit.
Preferably, the heat-sensitive section comprises a light-receiving element; and
at least one of the partition walls is constituted as a light-shielding wall for inhibiting light from the light source from being made incident on the light-receiving element.
The heat-insulating device may be configured such that the optical apparatus comprises a grating projection type moire device for capturing three-dimensional form information and pattern information of an object to be measured;
the light source comprises an illumination lamp for irradiating the object upon capturing the pattern information; and
the light-receiving element comprises an imaging section.
Since the three-dimensional image scanner in accordance with the first aspect of the present invention is configured such that the three-dimensional form information is captured by a grating projection type moire device, it can attain the following effects.
The grating projection type moire device does not necessitate a reference grating such as that in a grating shadow type moire device, whereby it will be sufficient if a virtual reference grating surface is set at a position conjugate with both of the projection grating and observation reference grating. This virtual reference grating surface has a size sufficient for the object to be measured, whereby the size of the object to be measured would not be restricted by the virtual reference grating surface. Also, the object to be measured can be disposed fore and aft through the virtual reference grating surface. As a consequence, the use of the grating projection type moire device increases the degree of freedom in measurement of the object. Also, since it is a moire device, the three-dimensional form information can easily be captured in a short time.
Therefore, the three-dimensional image scanner in accordance with the first aspect of the present invention can capture the three-dimensional form information of the object to be measured easily in a short time with a high degree of freedom in measurement.
In the above-mentioned configuration, in the case where the grating projection type moire device comprises grating moving means for moving at least one of a projection grating provided in a projection optical system of the grating projection type moire device and an observation reference grating provided in an observation optical system of the grating projection type moire device in a direction orthogonal to grating lines of both of the gratings within a plane orthogonal to optical axes of both of the optical systems, irregularities of the object can easily be determined when the directivity of change in moire fringes with respect to the movement of the grating is observed.
In this case, the grating moving means may move the projection grating alone, the observation reference grating alone, or both of them if they are not moved in the same phase.
Since the three-dimensional image scanner in accordance with the second aspect of the present invention is configured such that the three-dimensional form information is captured by a grating projection type moire device, and the pattern information is captured by an observation optical system of the grating projection type moire device, it can attain the following effects.
Namely, not only this three-dimensional image scanner can achieve the effects obtained by the three-dimensional image scanner in accordance with the first aspect of the present invention, but also it is unnecessary to remove a large reference grating in the grating projection type moire device such as that in the grating irradiation type moire device, in regard to the capturing of pattern information, whereby the pattern information can easily be captured by the observation optical system of the grating projection type moire device.
Therefore, the three-dimensional image scanner in accordance with the second aspect of the present invention can capture the three-dimensional form information of the object to be measured easily in a short time with a high degree of freedom in measurement, and can easily capture the pattern information of the object as well.
In this configuration, the pattern information has to be captured in the state where the object to be measured is placed in the state where no moire fringes are formed. Employable as a specific structure therefor is a structure comprising grating retracting means for retracting at least one of a projection grating provided in a projection optical system of the grating projection type moire device and an observation reference grating provided in the observation optical system to a position deviated from an optical path of the optical system corresponding thereto when capturing the pattern information. Since each of the projection grating and observation reference grating is much smaller than the reference grating of the grating irradiation type moire device, they can easily be retracted.
Since the three-dimensional image scanner in accordance with the third aspect of the present invention is configured such that the three-dimensional form information is captured by a grating projection type moire device, the pattern information is captured by an observation optical system of the grating projection type moire device, and an illumination lamp different from a projection lamp provided in a projection optical system of the projection type moire device is turned on when capturing the pattern information such as to irradiate the object, it can attain the following effects.
Namely, not only this three-dimensional image scanner can achieve the effects obtained by the three-dimensional image scanner in accordance with the first aspect of the present invention, but also it is unnecessary to remove a large reference grating in the grating projection type moire device such as that in the grating irradiation type moire device, in regard to the capturing of pattern information, whereby the pattern information can easily be captured by the observation optical system of the grating projection type moire device. Here, since an illumination lamp different from a projection lamp provided in the projection optical system of the projection type moire device is turned on when capturing the pattern information such as to irradiate the object, the shadow of the projection grating formed on the object by the projection lamp can be made substantially unremarkable, whereby the pattern information of the object formed with no moire fringes can be captured even when the projection grating and the observation reference grating are not retracted to a position deviated from the optical paths of the projection optical system and observation optical system.
Therefore, the three-dimensional image scanner in accordance with the third aspect of the present invention can capture the three-dimensional form information of the object to be measured easily in a short time with a high degree of freedom in measurement, and can easily capture the pattern information of the object as well.
In this configuration, though the projection lamp may be kept turned on while the illumination lamp is turned on, if the projection lamp is turned off, then no shadow of the projection grating will be formed, whereby the pattern information can be captured with higher accuracy.
Further, in this configuration, if the observation reference grating is retracted to a position deviated from the optical path of the observation system path when capturing the pattern information, then a sufficient quantity of light incident on the imaging device of the observation optical system can be secured. Also, in the case where the imaging device is a CCD camera or the like, artificial moire fringes can be prevented from occurring between the observation reference grating and the CCD or the like, whereby the pattern information can be captured with much higher accuracy.
Since the heat-insulating device in accordance with the fourth aspect of the present invention is configured such that, between a light source and a heat-sensitive section, a heat-insulating partition comprising at least two partition walls forming a cooling/heat-insulating path in order to inhibit the heat generated by the light source from being transmitted to the heat-sensitive section is provided, it can effectively inhibit the heat generated by the light source from being transmitted to the heat-sensitive section.
In this configuration, if the cooling/heat-insulating path is formed with an intake port for forcibly causing the outside air to flow through the cooling/heat-insulating path, and an exhaust unit, then the air flow from the intake port to the exhaust unit can be made very smooth, whereby the heat exhaust efficiency can be enhanced.
Also, in this configuration, when the heat-sensitive section comprises a light-receiving element, if at least one of the partition walls forming the cooling/heat-insulating path is formed as a light-shielding wall for inhibiting light from the light source from being made incident on the light-receiving element, then the heat-insulating device can also have a light-shielding function.
Further, in the case where the optical apparatus comprises a grating projection type moire device for capturing three-dimensional form information and pattern information of an object to be measured; the light source comprises an illumination lamp for irradiating the object upon capturing the pattern information; and the light-receiving element comprises an imaging section; the illumination lamp and the imaging section are often disposed relatively close to each other. Since the illumination lamp has a large heating value, whereas the imaging section is likely to be influenced by heat, employing the configuration in accordance with the fourth aspect of the present invention is effective in particular.